Efficient systemic therapies are needed for the treatment of resectable high risk and metastatic melanoma patients. Although cytokine therapy has demonstrated durable remissions, its use has been hampered by low response rates and high associated toxicity. Two strategies that could potentially lead to increased response rate and enhanced therapeutic effect will be investigated. 1) Administering combinations of cytokines rather than single cytokines could result in stronger, additive or synergistic anti-tumor effects. Using a combinatorial approach, cytokine combinations will be systematically tested for treatment of melanoma in a murine model. Six cytokines will be studied: IFNa, TNFa, IL-2, GM-CSF, IL-12 and IL-18. 2) To obtain greater cytokine concentrations in the tumor microenvironment, cytokine genes will be delivered intratumorally. In vivo electroporation, a method that has proven to induce consistent, durable high level protein expression in a number of tissues, will be used for gene delivery. Conditions for the optimal expression of transduced cytokines will be assessed. Combinations of cytokines will be systematically screened for induction of systemic anti-tumor activity. Successful combinations will be tested for rejection of metastases and induction of long-term protection. Under Phase II, optimal combinations will be selected for further characterization and preclinical development in large animals. PROPOSED COMMERCIAL APPLICATIONS: Pilot studies of Ichor's Electroporation Therapy (EPT) suggest that it could provide an effective means of the delivery of plasmid DNA into tumor tissue. Unlike other non-viral methods of gene transfer, EPT appears to be capable of reliably achieving high levels of gene expression. While this technology could potentially delivery a variety of nucleotide based therapies. Ichor believes that the delivery of cytokine genes represents the most appropriate approach for initial investigation. EPT has the potential to improve the therapeutic and toxicological profile characteristic of current methods of cytokine therapy. Initial indications would metastatic melanoma patients, for whom there are for therapeutic alternatives.